Home
Topics
IBM System z and Mainframe Systems
Mainframe operating systems and management
ISAM (Indexed Sequential Access Method)

Definition

ISAM (Indexed Sequential Access Method)

ISAM (Indexed Sequential Access Method) is a file management system developed at IBM that allows records to be accessed either sequentially (in the order they were entered) or randomly (with an index). Each index defines a different ordering of the records. An employee database may have several indexes, based on the information being sought. For example, a name index may order employees alphabetically by last name, while a department index may order employees by their department. A key is specified in each index. For an alphabetical index of employee names, the last name field would be the key.

ISAM was developed prior to VSAM (Virtual Storage Access Method) and relational databases.

Related glossary terms: Resource Access Control Facility (RACF), 64-bit processor, OLTP (online transaction processing), Teraplex (Teraplex Integration Center), P/390, VSAM (Virtual Storage Access Method ), real-time operating system (RTOS), SuperZap, ISPF (Interactive System Productivity Facility), scalability

This was last updated in November 2005

Posted by: Margaret Rouse

Email Alerts

Register now to receive SearchDataCenter.com-related news, tips and more, delivered to your inbox.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

More News and Tutorials

Exploring the changes in IBM's IMS 13 database management tool

IBM's latest version of its IMS database management tool features many enhancements to make enterprises consider the upgrade.
IBM's CICS Transaction Server 5.1 gears for cloud deployment

Open beta of CICS Transaction Server 5.1 introduces a bevy of features to reduce planned downtime and let CICS applications function in the cloud.
An in-depth look at IBM's transactional memory support facility

IBM's zEC12 mainframe introduced support for transactional memory. Learn the basics of Transaction Execution Facility.

Articles

Do you have something to add to this definition? Let us know.

Send your comments to techterms@whatis.com

Research More Tech Terms

Search thousands of tech definitions
Browse tech definitions
Browse Alphabetically:
- A
- B
- C
- D
- E
- F
- G
- H
- I
- J
- K
- L
- M
- N
- O
- P
- Q
- R
- S
- T
- U
- V
- W
- X
- Y
- Z
- #

Powered by WhatIs.com

File Extensions and File Formats

File Extension and File Formats List:

A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
#

Powered by WhatIs.com

More from Related TechTarget Sites

Windows Server
Enterprise Linux
Server Virtualization
Cloud computing
Virtual Data Centre

Windows Server
- Microsoft delivers patch updates for Windows Server 2012, Windows 8
  
  Microsoft delivered two critical and eight important bulletins in May's Patch Tuesday release, fixing issues in Windows Server 2012 and Office apps.
- Windows Azure Active Directory steps out of the shadows
  
  As Windows Azure Active Directory moves into general availability, we look at how it can help admins manage user authentication in the cloud.
- Steps to read XML files with PowerShell
  
  Wondering how to get PowerShell to read XML files? Our expert explains a few methods you could use.
Enterprise Linux
- SUSE Linux jumps on the open private cloud deployment train
  
  SUSE Linux Enterprise planning private cloud deployment with OpenStack weight behind it. NVIDIA works on Linux drivers for Optimus chips.
- Download Technology Priorities for 2012
  
  Download Technology Priorities for 2012
- Want one of the many Linux jobs out there? Time to go back to class
  
  Does extended education from the Linux Foundation and others help graduates meet the demands of today’s Linux jobs? Some say yes.
Server Virtualization
- Virtualization widens schism between server and networking teams
  
  Virtual networking has revived tensions between server and networking teams within data centers, but it's a dynamic both sides must embrace.
- Strike a common-sense balance when deciding what to automate
  
  Consider the many factors that determine the potential return on investment when deciding when and what to automate.
- How can I enable automated VM resource provisioning?
  
  As with many other facets of virtualization, VM resource allocation is becoming automated. Find out what tools you can use for automated provisioning.
Cloud computing
- Sequestration stymies federal government cloud ambitions
  
  The federal government is under mandates to consolidate data centers and deliver IT as a Service, but sequestration makes this easier said than done.
- VMware charges into public cloud IaaS fray as Dell exits
  
  Dell will discontinue its OpenStack and VMware vCloud-based public cloud offerings as VMware delivers its vCloud IaaS.
- Cloud migration obstacles remain for heavily regulated industries
  
  Financial, government and healthcare industries must overcome data security breaches and regulatory issues for a successful cloud migration.
Virtual Data Centre
- Download IT in Europe: August 2012
  
  This month's IT in Europe examines the views of the experts on the new EU framework, and assess what it means for European IT managers.
- Download Technology Priorities for 2012
  
  Download Technology Priorities for 2012
- Download IT in Europe: June 2012
  
  This month's IT in Europe examines how you can prepare for the new EU data regulations.

All Rights Reserved,Copyright - 2013, TechTarget